This won’t happen because China has boxed her self in. In three words, Three Gorges Dam!
For one, other than US no other regional power can target the Three Gorges. Secondly, attacking the dam would be in theory similar to attacking a city. It’s not like the Chinese don’t know that they face a nuclear threat.
And it’s not like they dont have the means to respond either.
I have visions of The Bridge over the River Kwai.